About a month ago, I noticed my 2000 was running warm (not in the red yet or smoking, but overhot). It has a 4.0 engine in it. I added water and replaced the radiator cap as the seal was slightly stiff on the old one. I filled the overfill bottle to the correct mark. I checked the manual and it said to check the overfill bottle monthly which was new to me as I've never had a vehicle I had to monitor the fluid that closely. Anyway, I've now had to add fluid (probably a pint each time) to get the bottle back to the fill line about every 2 weeks and I'm concerned that coolant seems to just be disappearing. Jeep has not overheated since I've been monitoring it. Jeep runs smooth as silk. No white rings at the fill cap or dip stick. No smell of burning antifreeze. No white exhaust. Jeep kept on garage floor so no sign of any fluid leaks. I just changed the oil today and no sign of antifreeze in the oil. So no indications of any sort that I have any seal leaks. Is this normal? Its in the 80-90 degree temps but does the coolant evaporate from the overfill bottle that much? I've never had a vehicle lose a pint of fluid every 2 weeks before but the Jeep shows no signs of leaks, nor coolant in the oil, nor coolant burning in the exhaust. Jeep has 90k on it.